After testing it, I put it in my parts bin for a planned project that never happened. Now I am thinking using it with my Raspberry Pi. It seems straight forward except for the pin labeled DS. I combed the net for a schematic with no result. I'm hoping you experts can shed some light on this.

It isn't connected to anything other than the header on the other side.

It IS connected, to the center (data) pin of the empty three pin device location in the corner. That's where you can put a DS18B20 temperature sensor and talk to it with OneWire. The schematic shows a 3.3k pull-up resistor for the OneWire bus but I suspect that would have been in the empty R7 location next to the crystal.

void setup(){ Wire.begin(); Serial.begin(9600); lcd.init(); delay(1000); lcd.clear(); lcd.backlight(); //Backlight ON if under program control lcd.setCursor(0,0); // Print a message to the LCD. lcd.print("Today it is");

I got my hands on an other RTC module which is the same type, but it was working! So my problem was at all time that the original RTC was broken Crap. But I don't know what could gone wrong in it? The eeprom or the IC maybe, but nothin other stuff.